1. Field of the Invention
The present invention relates generally to the field of computers and computer accessories. More specifically the present invention relates to a chair arm-mounted tray apparatus for supporting an item such as a keyboard in front of a user seated on a chair. The tray apparatus includes a panel defining a support deck on which the item is placed and a deck support frame fastened to the deck, the deck support frame having chair arm engaging means which removably secures the apparatus to the arms of a chair. The support frame positions the deck forwardly of the chair at an adjustable height and at an adjustable orientation relative to horizontal for ergonomic positioning of user arms and hands while the user operates a computer keyboard or mouse resting on the deck.
The deck support frame includes parallel and laterally spaced apart telescoping frame arms removably secured to chair arms by the chair arm engaging means. The chair arm engaging means preferably takes the form of first and second arm straddles in the form a U-shaped composite member including a pair of spaced apart straddle tines mounted to a distal arm segment. Both sets point in the same direction so that one set points inwardly toward the center of the chair and one set points away from the center. An extra distal arm segment preferably is also provided with a reversed straddle tine set, so that the reversed set arm segment can be used to complete one arm to point outwardly from the middle of the chair so that both sets point away from each other outwardly from the middle of the chair.
The straddle tines fit around each chair arm. As the frame arms pivot downwardly with their own weight as well as the weight of the deck and supported item, the tines rotate into abutting contact with the upper and lower surfaces of each chair arm, stopping further frame arm pivoting and thus supporting the frame arms and deck as the chair arms project forwardly and upwardly from the seat of the chair. Each arm straddle includes a clutch pivot joint at which the arm straddle engages the adjacent frame arm.
2. Description of the Prior Art
There have been various tray devices for connecting to or hanging from existing structures for supporting a wide variety of items, such as food at a drive-in restaurant. An example of a chair attached computer keyboard holder is found in Trimnell, U.S. Pat. No. 5,893,707, issued on Apr. 13, 1999. A problem with Trimnell is that it connects to a only certain type of chair legs not found on many chairs and is apt to be bumped by user feet. Another example is that of Yancz, et al., U.S. Pat. No. 5,356,059, issued on Oct. 18, 1994 for a basket or tray for attachment to a wheelchair. Once again, the attachment means appear to require the structure of a wheelchair, making its use very limited in the business world.
It is thus an object of the present invention to provide an arm chair mounted item support apparatus which can be removably secured to chair arms which thereby places an item supporting tray in front of a seated user.
It is another object of the present invention to provide such an apparatus which includes means for altering and selecting tray elevation from the user lap.
It is still another object of the present invention to provide such an apparatus which includes means for altering and selecting the tilt of the tray forwardly or rearwardly for maximized ergonomic use.
It is finally an object of the present invention to provide such an apparatus which is light weight, compact to store and transport, sturdy and inexpensive to manufacture.
The present invention accomplishes the above-stated objectives, as well as others, as may be determined by a fair reading and interpretation of the entire specification.
A chair arm-mounted tray apparatus is provided for mounting on a chair having chair arms with upper and lower chair arm surfaces and having a chair seat, for supporting an item, the apparatus including an item support deck for supporting an item; and a deck support frame fastened to the support deck, the deck support frame including a chair arm engaging structure for removably securing the apparatus to the arms of a chair, and including substantially parallel and laterally spaced apart frame arms removably secured to chair arms by the chair arm engaging structure, each frame arm including a proximal arm segment and a distal arm segment which includes the chair arm engaging structure; the chair arm engaging structure including first and second arm straddles, each of the first and second arm straddles including a substantially U-shaped member including two spaced-apart arm straddle tines defining a set of tines for fitting around one of the chair arms, including a clutch pivot joint at which the given arm straddle connects to the corresponding frame arm, so that as the frame arms pivot downwardly with their own weight and the weight of the support deck, the tines rotate into abutting contact with the upper and lower chair arm surfaces, thereby supporting the frame arms and the support deck.
The sets of straddle tines preferably both point outwardly from the chair. The sets of straddle tines alternatively both point in the same direction so that one set points toward the middle of the chair and the other set points outwardly from the chair. The straddle tines of each set are mounted to opposing ends of an elongate tine hub plate, and the hub plate has two opposing longitudinal hub plate ends including a hub plate axle port and a tine axle bolt passing through each tine axle port and through an axial bore in each straddle tine, so that each straddle tine is rotatably mounted to a hub plate end on a tine axle bolt. Each straddle tine preferably includes an inner tine support structure and an outer tine covering fitted over the inner tine support structure.
Each distal arm segment preferably includes two opposing hollow distal arm segment shells which fit together to form a distal arm segment body defining a mechanism cavity within the distal arm segment body; and where the distal arm segment shells are joined together with fasteners and each clutch pivot joint is contained within one of the mechanism cavities. Each ratchet mechanism preferably includes a ratchet gear having a ratchet gear circumference lined with ratchet teeth and being mounted on a ratchet gear axle mounted within the mechanism cavity, and connected to a corresponding U-shaped member; and a corresponding pawl pivotally mounted on a pawl axle mounted within the mechanism cavity and biased into engaging contact with the ratchet gear circumference by a pawl biasing spring. The chair arm-mounted tray apparatus preferably additionally a pointer element having two opposing pointed ends and port mounted to a corresponding U-shaped member to rotate with straddle tines.
A chair arm-mounted tray apparatus is provided for mounting on a chair having chair arms with upper and lower chair arm surfaces and having a chair seat, for supporting an item, the apparatus including an item support deck for supporting an item; and a deck support frame fastened to the support deck, the deck support frame including chair arm engaging structures for removably securing the apparatus to the arms of a chair, and including substantially parallel and laterally spaced apart frame arms removably secured to chair arms by the chair arm engaging structure, each frame arm including a proximal arm segment and a distal arm segment which includes the chair arm engaging structure; the chair arm engaging structure including first and second arm straddles, each of the first and second arm straddles including a substantially U-shaped member including two spaced-apart arm straddle tines defining a set of tines for fitting around one of the chair arms, including a clutch pivot joint at which the given arm straddle connects to the corresponding frame arm, so that as the frame arms pivot downwardly with their own weight and the weight of the support deck, the tines rotate into abutting contact with the upper and lower chair arm surfaces, thereby supporting the frame arms and the support deck; where the distal arm segments each include a radially protruding distal segment radial stem having a longitudinal radial stem spline, the proximal arm segments each include a radially protruding stem receiving tube containing a longitudinal radial stem spline channel for receiving the radial stem spline, each proximal arm segment further including a proximal segment slide ring portion secured at the segment tube proximal end; where the support deck includes a deck mounting assembly including for each frame arm a deck engaging structure at the arm proximal end with an external clutch tube having longitudinal and an external clutch tube spline slat which removably fits into longitudinal radial spline channel in the external clutch tube, a corresponding arm proximal segment slide ring portion fitted around the external clutch tube, the slide ring portion having internal axial spline groove each receiving an external clutch tube spline slat, so that the slide ring portion is longitudinally slidable along the external clutch tube and not rotatable about the external clutch tube; and an internal clutch tube extending within each one of the external clutch tubes and including an outward clutch segment having an outward clutch segment engaging structure, the outward clutch segment fitting into one of the external clutch tubes having an inward clutch segment having an inward clutch segment engaging structure engaging the outward clutch segment engaging structure of the corresponding the internal clutch tube, the inward and outward clutch segment engaging structure locking the external and internal clutch tubes against axial rotation relative to each other when mutually engaged, and permitting axial rotation relative to each other when disengaged. The chair arm-mounted tray apparatus where the outward clutch segment engaging structure includes a circumferential array of longitudinal outward clutch undulations and where the inward clutch segment engaging structure includes a circumferential array of longitudinal inward clutch undulations which engagingly receive the outward clutch undulations. The chair arm-mounted tray apparatus preferably additionally includes a release cap fitted into an end of each the external clutch tube and bearing against an outward end of the internal clutch tube, the release cap protruding out of the external clutch tube for manual access.
The chair arm-mounted tray apparatus preferably additionally includes a clutch spring biasing the internal clutch tube so that the inward and outward clutch undulations are releasibly biased into mutual registration and engagement, until axial manual pressure against the release cap overcomes the biasing of the spring and slides the outward undulations out of registration with the inward undulations and the external clutch tube and connected the proximal segment radial tube are free to pivot about the internal clutch tube, and thus to pivot the item support deck upward or downward relative to the chair.
The support deck has a deck rearward edge, and the apparatus preferably additionally includes a central deck mount tube segment connected to the deck rearward edge, and a deck tube segment secured to the deck rearward edge substantially coaxially with and spaced apart from the central deck mount tube to define a clutch space, where each external clutch tube containing an internal clutch tube fits into one of the clutch spaces, and each internal clutch tube extends into the central deck mount tube segment and the release cap extends through the adjacent the deck mount tube segment, so that the internal and external clutch tubes are retained.
A chair arm-mounted tray apparatus is further provided for mounting on a chair having chair arms with upper and lower chair arm surfaces and having a chair seat, for supporting an item, the apparatus including an item support deck for supporting an item; a telescoping deck panel, where the support deck additionally includes a deck lower surface and the deck lower surface includes a pair of guide tracks slidably retaining the telescoping deck panel; so that the deck panel is slidable outwardly beyond the support deck for extending the support deck and for slidable underneath the support deck for compact storage; and a deck support frame fastened to the support deck, the deck support frame including a chair arm engaging structure for removably securing the apparatus to the arms of a chair, and including substantially parallel and laterally spaced apart frame arms removably secured to chair arms by the chair arm engaging structures, each frame arm including a proximal arm segment and a distal arm segment which includes the chair arm engaging structure; the chair arm engaging structure including first and second arm straddles, each of the first and second arm straddles including a substantially U-shaped member including two spaced-apart arm straddle tines defining a set of tines for fitting around one of the chair arms, including a clutch pivot joint at which the given the arm straddle connects to the corresponding the frame arm, so that as the frame arms pivot downwardly with their own weight and the weight of the support deck, the tines rotate into abutting contact with the upper and lower chair arm surfaces, thereby supporting the frame arms and the support deck.
The deck panel has edge portions and the guide tracks preferably are each L-shaped protrusions from the deck lower surface oriented to open toward each other and retaining the edge portions. The support deck preferably includes a panel abutment structure and in this instance the deck panel additionally includes a stop structure connected to the deck panel for abutting the deck abutment structure when the deck panel is slid to full extension for stopping the deck panel from sliding entirely out of the guide tracks.